JP2737419B2 - Surface temperature distribution measuring device for curved objects - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type temperature distribution measuring device for measuring a temperature distribution on the surface of an "object having a curved surface" such as a rod or a tube.

[0002]

2. Description of the Related Art Conventionally, as one of the devices for measuring the temperature distribution on the surface of an object such as a heated steel material in a non-contact manner, there is provided a mechanism for scanning the surface of the object to be measured by combining a reflecting mirror with a radiation thermometer. "One-dimensional scanning type temperature distribution measuring device"
It has been known. As shown in FIG. 4, for example, this apparatus scans the measurement field of the radiation thermometer 1 with a reflecting mirror such as a rotating mirror 2 to measure the temperature distribution on the surface of the measured object 3 in a wide range. is there. Note that reference numeral 4 in the drawing denotes a lens.

However, as shown in FIG. 5, the intensity of the radiated light emitted from the surface of the object differs between the “normal direction of the radiation surface” and the “direction at an angle θ to the normal”. Between the radiation intensity I (θ) in the direction forming an angle θ with respect to the normal and the radiation intensity I _{0 in the} normal direction is expressed by I (θ) = ε (θ) I ₀ · cos θ. Lambert's cosine law holds. Here, ε (θ) is the emissivity in the θ direction.

For this reason, as shown in FIG. 6, when a temperature distribution measuring device having the above-mentioned scanning reflector is used to measure the temperature distribution on the surface of a wire (5) during rolling, for example, a point A in FIG. It is possible to measure the temperature accurately if it is within the range where the influence of "angle dependence of the radiation intensity from the measurement surface" on the temperature measurement can be neglected. However, as shown at point B, the displacement angle from the normal direction However, accurate measurement of the temperature is impossible at a site where the radiation intensity is large, due to the angular dependence of the radiation intensity. As can be inferred from FIG. 6, the range in which the angular dependence of the radiation intensity can be neglected is smaller for an object having a curved surface than for a planar object. It was extremely difficult.

On the other hand, Japanese Utility Model Laid-Open No. 1-97227 discloses that
As an apparatus for measuring the circumferential temperature distribution of an elongated member, FIG.
A temperature distribution measuring device is disclosed in which one radiation thermometer 1 is fixed to a rotating wheel 6 installed on a concentric outer circle of a measured object 3 as shown in FIG. In other words, this device is to rotate the rotating wheel 6 so that the radiation thermometer 1 orbits around the measured object 3 to measure the temperature distribution over the entire circumference of the measured object 3.

However, in the apparatus shown in FIG. 7, there is a limit in rotating the rotating wheel 6 on which the radiation thermometer 1 is installed at a high speed. When the target object moves at a high speed, it is difficult to measure the temperature distribution over the entire circumference and the entire length of the measurement target object. In addition, it has been pointed out that since the radiation thermometer 1 must be rotated, the size of the apparatus becomes large and the installation place is limited.

As described above, there has been no simple non-contact type device that can accurately and quickly measure the temperature distribution on the surface of an object, particularly on the surface of a curved object over a wide range.
This has been a considerable obstacle in promoting production of various articles and improvement of processing means.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problem, and an object of the present invention is to provide an apparatus for measuring a temperature distribution on the surface of an object by receiving heat radiation from the object. As shown in the figure, "a plurality of single-core optical fibers 7 whose one ends can be opposed to the surface to be measured of the object 3 from the normal direction" for receiving and transmitting the heat radiation light from the object 3 to be measured. And a configuration in which one unit of the photoelectric conversion element of the photodetector 8 is connected to the other end of each optical fiber 7, or in addition to this, the light receiving of the optical fiber 7 is further performed. By disposing a field stop 9 for preventing the fields of view of the optical fibers 7 on the surface of the object 3 to be measured from overlapping with each other at one end (one end side) so as to increase the measurement field resolution, the surface temperature distribution of the curved object is obtained. High accuracy and high speed over a wide range And it has a great feature in the point "which is adapted to measure. Note that reference numeral 10 in the figure denotes a signal processing device.

When measuring the temperature distribution by the apparatus of the present invention, the light receiving portion of the optical fiber is used to secure the measurement accuracy.
("One end" or "tip") must be opposed to the surface to be measured of the object to be measured from the normal direction, but the facing direction does not require extraordinary strictness and is slightly different from the normal direction. There is no problem if an angular deviation occurs. Also, in order to make the size of the measurement visual field on the surface to be measured of the object to be measured uniform between the optical fibers, the light receiving portion (tip) of each optical fiber must be positioned at the same distance from the surface to be measured. It is needless to say that it is preferable to perform the measurement (for example, if the surface to be measured is a cylindrical surface, the tip positions are aligned on the concentric outer circle).

When the one-dimensional photodetector is used as the photodetector, the other end (rear end) of each optical fiber is arranged in a line at a fixed interval and each of the "one unit of the photoelectric conversion element" 1
When a two-dimensional photodetector is applied as a photodetector, the two-dimensional photodetector is arranged in a plurality of rows at regular intervals, and is coupled one-to-one with each “one unit of the photoelectric conversion element”. Connected, but the "one unit of photoelectric conversion element" of the photodetector
For example, a photoelectric conversion element is a CCD element (Charge Coupl
ing Device), one unit of “1 pixel” or “2 or more pixels” of the plurality of pixels is referred to as one unit, and the number of pixels in one unit may be appropriately determined.

[00011]

According to the surface temperature distribution measuring device according to the present invention, a "medium for receiving heat radiation light from the measured object and transmitting the light to the photodetector" is provided between the measured object and the photodetector. With the optical fiber interposed, the position and direction of the heat radiation can be freely set, and the heat at the equidistant position over a wide range of the surface of the object whose temperature distribution is to be measured. Since the emitted light can be detected at an angle that is not affected by the “radiation intensity angle dependence”, a highly accurate temperature distribution measurement can be performed even for a curved object. Further, since the structure of the device is simple and the device can be miniaturized, restrictions on the installation location are reduced.

The rear end of each optical fiber is connected to each "one unit of the photoelectric conversion element" of the one-dimensional or two-dimensional photodetector.
Since they are connected in a one-to-one relationship, the thermal radiation received by each optical fiber is converted into an electrical signal by the photodetector, and the electrical scanning can be performed to measure the temperature distribution at high speed. Become. Further, in the case where a field stop is provided in the heat radiation receiving portion of the optical fibers, the field of view of each optical fiber on the surface of the object to be measured is reduced so that the area of the temperature measurement portion by each optical fiber is reduced. Overlap can be avoided, and the measurement field resolution can be increased.

[00013]

The present invention will be described more specifically with reference to the following examples. FIG. 2 is a schematic diagram of the configuration of the temperature distribution measuring device according to the embodiment of the present invention, and shows a situation in which the wire 11 being rolled is a target object whose temperature distribution is to be measured.
That is, in the apparatus shown in FIG. 2, the heat radiation light (not shown) from the wire 11 being rolled is received by the optical fiber 7 provided with the field stop 9 and transmitted to the photodetector 8, and the light is transmitted to the photodetector 8. The surface temperature distribution of the wire 11 is measured by converting it into an electric signal by the CCD element 12 of the detector 8 and converting the temperature by the signal processing device 10.

Here, as the optical fiber 7, for example, 20 single-core optical fibers (core 100 μm, clad 140 μm) are applied, and the tip of the optical fiber 7 is positioned on the concentric outer circle of the wire 11. The wire 11 is disposed so as to surround the outer periphery of the wire 11 so as to face the center of the wire 11 (ie, to face the outer peripheral surface of the wire from the normal direction). A field stop 9 is provided at the tip of all the optical fibers 7 so that the field of view corresponds to the outer periphery of the wire 11.

The rear ends of all the optical fibers 7 are arranged in a line at intervals of 200 μm and connected to a CCD element having 128 pixels (pixel interval of 50 μm) of a one-dimensional photodetector. C
The connection with the CD element 12 is made such that one core portion of the optical fiber is connected to two CCDs as shown in the figure. Therefore, the "radiation light from the wire" transmitted by each optical fiber is C
The signal is received by two pixels of the CD and converted into an electric signal, and the total output is a signal for one optical fiber, and the signal processing device
Converted to temperature by 10. Similarly, for all the optical fibers, the emitted light is converted into an electric signal, and the temperature is converted, and the temperature distribution of the wire is displayed.

FIG. 3 shows an example of the result of measuring the temperature distribution on the outer peripheral surface of the wire rod during rolling by this apparatus. As described above, the use of the apparatus of the present invention makes it possible to accurately and accurately measure the temperature distribution over the entire circumference of the wire being rolled.

[00017]

As described above, according to the present invention, the temperature distribution on the surface of an object having a curved surface such as a rod or a tube can be measured at high speed, high accuracy, and high resolution. Industrially useful effects are provided, such as a compact surface temperature distribution measuring device with a small restriction such as that described above.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a surface temperature distribution measuring device according to the present invention.

FIG. 2 is a schematic diagram of a configuration of a temperature distribution measuring device according to an embodiment of the present invention.

FIG. 3 is a graph showing a result of measuring a temperature distribution on an outer peripheral surface of a wire during rolling by an example apparatus.

FIG. 4 is an explanatory diagram of a conventional temperature distribution measuring device.

FIG. 5 is an explanatory diagram of an intensity difference depending on a radiation angle of radiation light radiated from an object surface.

FIG. 6 is an explanatory diagram relating to a problem of a conventional temperature distribution measuring device.

FIG. 7 is an explanatory diagram relating to another example of the conventional temperature distribution measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radiation thermometer 2 Rotating mirror 3 Object to be measured 4 Lens 5 Wire 6 Rotating wheel 7 Optical fiber 8 Optical detector 9 Field stop 10 Signal processing device 11 Rolling material 12 CCD element

Claims (2)

(57) [Claims] 1. An apparatus for receiving a thermal radiation from an object and measuring a temperature distribution on the surface of the object, comprising a method for receiving and transmitting the thermal radiation. A plurality of single-core optical fibers which can be opposed to each other from the line direction, and one end of each optical fiber is connected to one unit of a photoelectric conversion element of a photodetector. , Surface temperature distribution measuring device for curved objects. 2. A light receiving portion of an optical fiber for receiving thermal radiation light from an object to be measured is provided with a light receiving section for improving the resolution of the measurement visual field by avoiding overlapping of the fields of view on the surface of the object to be measured. The surface temperature distribution measuring device for a curved object according to claim 1, wherein a field stop is provided.